Virtual Private Networks

Learning Objective

You will understand how Virtual Private Networks (VPNs) function as a circumvention tool for censorship by gaining firsthand experience using a VPN. Through empirical measurements and traffic inspection, you will explore how VPNs affect network paths, performance (e.g., ping and page load time), and traffic visibility.

Part 1: Experience with Virtual Private Networks

Step 1: Install a Free VPN

• Choose and install a free VPN such as ProtonVPN, Windscribe, or TunnelBear.
  • Register for a free account and install the VPN on your laptop (desktop preferred for the next steps). Note: Free versions may limit server selection, but that’s fine for this assignment.

Step 2: Select a Server and Connect

• Connect to a VPN server in another country (e.g., Netherlands or Japan). Take note of which server location you choose.

Step 3: Measure Latency and Load Time

For each of the tests below, perform them once with the VPN disabled and once with the VPN enabled.

Ping Test

• Open a terminal and run:

    ping -c 5 www.google.com
    ping -c 5 www.bbc.com
  

• Record the average round-trip time (RTT).

Page Load Time

• Open a browser and load a news website (e.g., https://www.bbc.com or https://www.nytimes.com).
  • Use the browser’s Developer Tools (usually under “Network”) to measure how long the page takes to fully load.
    • Record the total load time.

Traceroute

• Run a traceroute to a site like www.wikipedia.org:

  • On Mac/Linux: bash traceroute www.wikipedia.org

  • On Windows: cmd tracert www.wikipedia.org

• Compare the number of hops and the intermediate IPs between VPN and non-VPN connections.

Step 4: Capture and Inspect Network Traffic

• Open Wireshark (install it if you haven’t already).
• Start a capture on your primary network interface (typically Wi-Fi or Ethernet).
• Browse to a site like www.bbc.com with and without the VPN.

• Stop the capture after each session and examine:

• Destination IP addresses (filter using ip.dst)
• Whether DNS queries or HTTP/HTTPS traffic are visible
• Whether the destination IPs differ with the VPN on vs. off

Optional Bonus: Try accessing a site that is known to be blocked in some countries (e.g., Deutsche Welle or Radio Free Asia) and note whether access changes when connected to different VPN locations.

Part 2: Discussion

Answer the following questions based on your experiment:

1. Performance: How did latency and page load times change when the VPN was enabled? Were they consistent across multiple trials?
2. Routing: How did the network path (number of hops and route) change when using the VPN? Why do you think that is?
3. Visibility: What differences did you observe in the Wireshark capture with and without the VPN?
4. IP Addressing: How did the destination IPs or domains differ between the two cases? Were you able to identify the VPN endpoint?
5. Security and Privacy: Based on your traffic inspection, what does the VPN appear to encrypt or obscure? What remains visible?
6. Censorship Circumvention: Reflecting on this experience, how might a VPN help users bypass censorship in a restrictive regime? What limitations or risks might still remain?